var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

// var indexRouter = require('./routes/index');
// var usersRouter = require('./routes/users');


// 1引入代理服务器
const { createProxyMiddleware } = require('http-proxy-middleware');

// 2 配置代理服务器
const options ={
  target: 'http://127.0.0.1:4000',// target 配置后台服务器的地址
  changeOrigin: true, // 支持跨域
  pathRewrite:{   //路径重写
    '^/api':"/"  //把发过来请求的ajax凡是url是api开头的都拦截下来并把api修改成跟目录/
 }
};


//3 创建代理服务器 把配置代理服务器传到引入代理
const studentServerProxy = createProxyMiddleware(options);



var app = express();


// 静态资源
app.use(express.static(path.join(__dirname, 'public')));



//4 注册代理服务器 
//注意： 位置必须在处理静态资源之后，注册其他的中间件之前
//挂载代理服务器
app.use('/', studentServerProxy);


// view engine setup
// app.set('views', path.join(__dirname, 'views'));
// app.set('view engine', 'jade');

// app.use(logger('dev'));
// app.use(express.json());
// app.use(express.urlencoded({ extended: false }));
// app.use(cookieParser());
// app.use(express.static(path.join(__dirname, 'public')));

// app.use('/', indexRouter);
// app.use('/users', usersRouter);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;
